Turnbull, Trump aim for mateship in US

Malcolm Turnbull says gun control is for Americans decide, as the debate continues while he visits.

US President Donald Trump will welcome Prime Minister Malcolm Turnbull to the White House.

A little over a year after their "most unpleasant" phone call, US President Donald Trump will welcome Australian Prime Minister Malcolm Turnbull to the White House with pomp and ceremony designed to erase any lingering ill will.

Just like a blockbuster Hollywood film marketing campaign, Friday's visit has been branded by the Australian delegation with a slogan: 100 Years of Mateship.

It is the 100th anniversary of the World War I battle of Hamel in northern France where US and Australian troops fought alongside each other for the first time, a milestone that war buff Mr Trump will find appealing.

After a ceremonial welcome on the White House South Lawn, Mr Trump and Mr Turnbull will spend one-on-one time in the Oval Office and engage in a working lunch while First Lady Melania Trump and Lucy Turnbull break away for their own private lunch.

"The United States is our most important strategic partner, it is our most important economic partner," said Mr Turnbull, speaking to reporters near the front gate to the White House on Thursday.

"Our relationship is critically important so we work to strengthen it and defend it."

Mr Trump has been dogged by scandals in his first year in office, but it appeared as though it would be Mr Turnbull facing curly questions about Deputy Prime Minister Barnaby Joyce at the scheduled joint White House press conference (4.30pm AEDT on Saturday).

Mr Joyce's announcement on Friday he would be stepping down as deputy will likely extinguish that.

Mr Turnbull and Mr Trump have a long list of issues to discuss on Friday including the North Korean nuclear threat, the possible US return to the Trans-Pacific Partnership, tax reform in both nations, the proposed US-Australia-Japan-India defence and infrastructure pacts to counterbalance China and potential US tariffs on Australian steel and aluminium.

"The strong and committed presence of the United States in our region has been the sheet anchor for that rules based order and for that prosperity," Mr Turnbull said.

Mr Turnbull said he will not attempt to get involved in the gun control debate that is raging across the US since last week's Florida high school shooting, despite Mr Trump consumed by the issue in recent days and Australia used as a shining example of gun law reform.

"It's not for me to get involved in a contentious domestic political debate here," Mr Turnbull said.

Mr Turnbull also indicated he would not raise the asylum-seeker deal that infuriated Mr Trump in that infamous phone call on January 28, 2017 that was scheduled to last one hour but the president abruptly ended after just 24 minutes.

"Where do they come from?" Mr Trump asked Mr Turnbull, according to the call's transcript leaked to the Washington Post.

"Are they going to become the Boston bomber in five years? Or two years?"